Method of making heat exchangers



June 19, 1945;

l. B. MANNING METHOD OF MAKING HEAT EXCHANGERS Filed Sept. 19, 1942 Patented Jupe 19, 1945 Thermek Corporation, Chicago,

tion of Delaware Ill., -a corpora- Application september 19,1942, serial No. 458,977

4 claims. (ci. 113-118)Vlr t The invention relates to heat exchangers provided with heat transfer elements of sheet metal. One object of the invention is to provide an improved method for producing heat exchangers l with sheet metal elements for heat -conduction which utilizes continuous strips with integral rows of tongues projecting angularly from the margin of the strips to provide extended surfaces of high conductive eiiiciency'and in which one wall of the uid conduit is provided with transfer elements which extend from both of its faces.

.Another object of the invention is to provide animproved method for producing heat exchangers with annular conduits with sheet metal' V.

heat transfer elements which comprise continuous strips and integral rows of tongues projecting angularly away from the strips for efiicient heat conduction.

Another object of an improved heat exchanger which is provided with sheet metal heat transfer elements composed of continuous strips and angularly 'extending tongues on both faces of one of the walls of a conduit.

Another object of the invention is to provide a. heat exchangerof the annular conduit type with efficient heat transfer elements.'

Other objects of the invention will appear fromA the detailed description. Theinvention consists in the several novel fea- -tures which are hereinafter set forth and more particularly defined by claims at the conclusion hereof.

In the drawing:

Figure 1 is a perspective of a portion of kone of the heat transfer elements before it is joined to a conduit wall.

Figure 2 is a transverse section of the element shown in Fig. 1. I

Figure 3 is a section illustrating the simultaneous welding of a pair of heat transfer elements to the opposite faces of a conduit wall.

Figure 4.is a section illustrating the shape in which the tongues are bent after the elements have been bonded to the conduit wall.

Figure 5 is a transverse section of a heat exchanger with two annular conduits embodying the invention.

Figure 6 is a transverse section of a heat exchanger of the box type.

The invention utilizes sheet metal elements for providing extended surfaces on walls for heat conduction. The elements are fabricated from sheet metal which is cut to provide continuous strips I0 and rows of integral tapered tongues the invention is to provide Il and i2 'along the longitudinal margins of the strips respectively. The tongues and strips are rst cut from fiat sheet metal into at blanks. t

The tongues are next bent to extend angularly away from one face of the strip. Strips I0 are then bondedto a sheet metal plate i3 which is adapted to f orm one wall of a fluid-conduit. The facesof the strips from which'no tongues extend are arranged in parallel relation and in juxtaposition on opposite sides of the plate i3 and passed between electric welding rolls d, as

illustrated in Fig. 3, to bond strips to the opposite faces of the plate vlil by continuous welds d1 which extend substantially across the contiguous faces of the strips I 0. Initially, the tongues il and I2 .are bent to extend away from the strips I0 at such angles that the welding rolls d can pass between the rows of tongues along the opposite margins of the strips. As shown, the tongues are arranged in transverse pairs on each strip with one tongue Ilof each pair extending substantially at right angles to the face of strip I0 and the other tongue .l2 of each pair extending `obliquely from said face. After the strips I0 have been bonded to the plate |'3 as shown in Fig. 3, the right-angled tongues Il of each transverse pair are bent into substantially parallel relation with the oblique or inclined tongue I2 of each transverse pair, as illustrated in Fig.

4. The alternate transverse pairs of tongues are l bent to extend obliquely in opposite directions from the strip so that one row of transverse pairs of tongues will `extend crosswise of the next transverse row of pairs.

Fig. 5 illustrates a heat exchanger with an inner annular conduit a for one fiuid and an outer annular conduit b for another fluid. In fabricating this type of heat exchanger, the plate or sheetv I3, after the strips have been bonded to both of its faces, is bent to a cylindrical shape as illustrated in Fig. 5, to form a continuous cylindrical wall c with heat transfer elements extending outwardly from its outer periphery and inwardly from its inner periphery This `may be formed from a singleplate, or if desired the plates may be bent into arcuate sections and their edges secured together to form a cylindrical wall. v

A plate or sheet of metal is then extended around the outer ends of the tongues projecting from the outer periphery of the wall c to form an annular outer wall b1 for the conduit b. A cylindrical shell or plate is forcedbetween the ends of the tongues which projects inwardly from.

wall c to form the inner wall a1 for the conduit a. 'I'he Wall c forms the inner wall of the conduit b and the outer wall of the conduit a. 'Ilie wall al may be made of tubing or of a sheet bent to cylindrical form with edges welded together.

This exemplifies a methodpf fabricating 'heat exchangers with sheet metal transfer elements bonded to both faces of one wall for use in separate iiuidconduits andalso alow'cestfmethod for fabricating tubular conduitswlth heat transfer elements bonded thereto. The tongues are iiexible so they will resiliently engage and contact with the inner periphery of wall b1 and the outer periphery oi wall al respectively.

In Fig. 6 the invention is illustrated in con.- nection with a box-type of heat-exchanger vprovided with two separate compartments or conduits a2 and b2. In fabricating this .type a sheet I3 with strips l bonded to its opposite faces-and with tongues extending angularly therefrom, as illustrated in Fig. t are fabricated as before described. Sheet l3 with4 the heat transfer-elements bonded thereto forms the dividing wall c2 between conduits a2 and b2. The outer-wall of compartment or conduit a2 is formed by a metal plate a3 with a flanged rim ca and the outer wall of compartment or conduit b2 is formed by a plate-of metal b3 with a flanged rim b4. The anges on the rims of plates b3 and c3 with the sheet I3 between them to form the dividing wall c2 are suitably welded or otherwise secured together as at I5, to complete the box with two separate conduits; In this case the tongues may be iiexible so they will engage the outer wall of the box. Fluids flowing through the conduits or compartments a2 and b2 respectively will contact the edges and faces of the tongues for efficient thermal conduction. The tongues on the strips I0 may be of any desired length and extend at any desired angie across the conduit so that the desired area of extended surface for thermalconduction will `V be attained.

The invention exemplifies a simple method "for providing a single conduit wall with sheet metal heat transfer elements on'both faces thereof and of sucient area for efficient thermal conduction. It also exemplifies a simple vmethod for fabricating heat exchangers having annular conduits Awith efficient heatvtransfer elements. It also exemplifies a heat exchanger provided with sheet metal heat transfer elements which are efficient in thermal conduction and can be produced at a low cost of fabrication.

The invention is not to be understood as restricted to the details' set forth -since these may be modified within the scope of the appended claims without departing 'from the spirit and scope of the invention.

Having thus described the invention, what I claim as new and desire to secure by Letters Patent is:

l. That improvement in making heat exchangers which comprises cutting nat sheet metal into continuous Vstrips with rows of integral gamelle tongues along their longitudinal margins, then bending the tongues to extend angularly away from the strips, then bonding a series of said strips in parallel relation to one of the faces of a flat metal plate with the tongues extending away from said faces to form extended surfaces for heat conduction, then bending the plate with the strips thereon transversely of the strips to forni an annularcondnit wall'with the strips extending longitudinally of the conduit, and then securing an annular wall around the free end of the tongues -to form an annular conduit between the walls.

2. That improvement in making heatexchangers'which comprises cutting flat sheet metal into `continuous Astrips with rows of integral tongues along their longitudinal margins, then bending .the tongues to extend angularly away from the strips, then simultaneously bonding pairs of said strips in parallel relation to one of thefaces of a fiat metal plate with the tongues extending away from said faces to form extended surfaces for heat conduction, then bending the plate with thefstrips thereon transversely of the strips-toform an annular conduit wall with the strips extending longitudinally ofthe conduit, and then securing an annular wall around the free end of the'tongues .to form an annular conduit between the walls.

That improvement in making heat exchangers which comprises cutting fiat sheet metal into continuous strips with rows of integral tongues along their longitudinal margins, then bending the tongues to-extend angularly away from the strips, then'bonding a series oi said strips in parallel relation to each of :the opposite faces of a iiat metal plate with the `tongues extending away from the opposite faces ofthe plate .to form extended faces'for heat conduction, then bending the plate with'the' strips secured on the opposite faces of the sheet .transversely of the strips to form an annular conduit 'wall with the strips extending longitudinaliy of the conduit, and then securing an annular wail around the free ends of thetongues on one side of the bent plate to form an annular conduit.

4. That improvement in making heat exchangers which. comprises cutting fiat sheet metal into continuous strips with rows of integral tongues along their longitudinal .mai-girls, then bending the tongues to extend angulariy away from the strips, 'then simultaneousiybonding pairs of said strips inparaliel and transversely aligned relation to eachof the opposite faces ci' a fiat-metal plate with the tongues extending away from the opposite faces of the plate to form extended'faees for'heatconduction, then-bending the plate with the .strips secured on its opposite faces transversely ofthe strips to form an annular conduit wall with the strips extending longitudinally of the conduit, and then securing annular walls around the free ends. of the .tongues onboth sides of the heut zilatetolorm a pair of annular conduits. l

LUCIUS B. MANNING. 

